The invention relates to a charge control apparatus for controlling the operation of a reciprocating internal combustion engine, especially a gasoline engine. The invention also relates to a method for controlling the operation of a reciprocating internal combustion engine, especially a gasoline engine.
One of the reasons that reciprocating internal combustion engines, especially reciprocating internal combustion engines controlled via a throttle valve and operated as a four cycle engine, have an increasingly higher specific fuel usage in correspondence with decreasing loading—that is, fuel usage per given work unit—is attributable to the throttle loss. An increasing underpressure or vacuum is formed downstream of the throttle valve in the volume of the suction intake between the throttle valve and the intake valve in correspondence with an increasingly more frequently closed throttle valve and this increasing vacuum reduces during the period during which the intake valve is closed. The energy stored in this volume which is impacted by the vacuum is consequently lost for use otherwise as work energy. The vacuum created by the downward movement of the piston during the intake stroke causes a dissipative loading change side in the P-V (pressure-volume) diagram